Transition metal catalyzed oxidation of organic molecules is a major class of chemical transformation both in the laboratory synthesis of fine chemicals and in the manufacture of large-volume petrochemical-based feedstocks. While the chemical community has continued to evolve a deeper understanding of the mechanistic aspects of homogeneous catalytic reactions, several significant challenges remain, including the development of catalysts with enhanced selectivity, greater stability, better atom economy, and minimal environment impact (green oxidation chemistry).
An unmet goal of current green oxidation chemistry is the exploitation of dioxygen, as opposed to oxygen atom transfer reagents (i.e. peroxides, oxygen atom donor molecules, etc.), in metal-based catalysis, a direct consequence of the challenges of controlling or eliminating non-selective free-radical chain reactions. Activated oxygen sources require expensive and/or potentially unstable reagents, whereas dioxygen is inexpensive and chemically stable relative to peroxides. However, the necessity of excess reducing agent to perform catalytic chemistry with oxygen frequently results in unwanted radical chemistry or poisoned, inactive catalysts.